Publications
Filter Total Items: 1998
Effects of habitat fragmentation on passerine birds breeding in Intermountain shrubsteppe
No abstract available.
Authors
Steven T. Knick, John Rotenberry
Residency and movement patterns of wintering dunlin in the Willamette Valley of Oregon
In the winters of 1998–1999 and 1999–2000, we tracked 67 radio-marked Dunlin (Calidris alpina) throughout the complex agricultural landscape of the Willamette Valley of Oregon. Individual birds were tracked across 8-week sampling periods and indicated a high degree of regional fidelity throughout the three winter sampling periods. Birds exhibited varied degrees of fidelity to specific wetland site
Authors
Peter M. Sanzenbacher, Susan M. Haig
American white pelican soaring flight times and altitudes relative to changes in thermal depth and intensity
We compared American White Pelican (Pelecanus erythrorhynchos) soaring flight times and altitudes to model-produced estimates of thermal depth and intensity. These data showed that pelican soaring flight was confined to the thermal layer, and that the vertical extent of the soaring flight envelope increased with increases in thermal depth. Pelicans soaring cross-country between foraging and breedi
Authors
H.D. Shannon, G.S. Young, M. Yates, Mark R. Fuller, W. Seegar
Comparative diversity and composition of cyanobacteria in three predominate soil crusts of the Colorado Plateau
Terminal restriction fragment length polymorphism (TRF or T-RFLP) analysis and 16S rDNA sequence analysis from clone libraries were used to examine cyanobacterial diversity in three types of predominant soil crusts in an arid grassland. Total DNA was extracted from cyanobacteria-, lichen-, or moss-dominated crusts that represent different successional stages in crust development, and which contrib
Authors
Elizabeth Redfield, Susan M. Barns, Jayne Belnap, Lori L. Daane, Cheryl R. Kuske
Abundances of northwestern salamander larvae in montane lakes with and without fish, Mount Rainier National Park, Washington
In Mount Rainier National Park, the northwestern salamander usually inhabits relatively large and deep lakes and ponds (average size = 0.3 ha; average depth > 2 m) that contain flocculent, organic bottom sediments and abundant coarse wood. Prior to 1970, salmonids were introduced into many of the park's lakes and ponds that were typical habitat of the northwestern salamander. The objective of this
Authors
Gary L. Larson, Robert L. Hoffman
Golden eagles in the U.S. and Canada: Status, trends, and conservation challenges
We reviewed the literature to assess status and population trends and to identify mortality
factors affecting Golden Eagle populations in the U.S. and Canada. Nesting populations in Alaska and Canada are stable, but some nesting populations in the western U.S. have declined. Small but steady declines in the intermountain West have been associated with shrub loss and declining jackrabbit populatio
Authors
Michael N. Kochert, Karen Steenhof
Optical characteristics of natural waters protect amphibians from UV-B in the U.S. Pacific Northwest
Increased exposure to ultraviolet-B (UV-B) radiation has been proposed as a major environmental stressor leading to global amphibian declines. Prior experimental evidence from the U.S. Pacific Northwest (PNW) indicating the acute embryonic sensitivity of at least four amphibian species to UV-B has been central to the literature about amphibian decline. However, these results have not been expanded
Authors
Wendy J. Palen, David E. Schindler, M. J. Adams, Christopher A. Pearl, R. Bruce Bury, S. A. Diamond
Rangeland health attributes and indicators for qualitative assessment
Panels of experts from the Society for Range Management and the National Research Council proposed that status of rangeland ecosystems could be ascertained by evaluating an ecological site's potential to conserve soil resources and by a series of indicators for ecosystem processes and site stability. Using these recommendations as a starting point, we developed a rapid, qualitative method for asse
Authors
David A. Pyke, Jeffrey E. Herrick, Patrick Shaver, Mike Pellant
Long-term patterns of diameter and basal area growth of old-growth Douglas-fir trees in western Oregon
Diameter growth and age data collected from stumps of 505 recently cut old-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees at 28 sample locations in western Oregon (U.S.A.) indicated that rapid early and sustained growth of old Douglas-fir trees were extremely important in terms of attaining large diameters at ages 100a??300 years. The diameters of the trees at ages 100a??300 years
Authors
Nathan Poage, J. C. Tappeiner
Ascaphus trueii (Tailed frog). Albinism
No abstract available.
Authors
Christopher A. Pearl, D.J. Major, R. Bruce Bury
Growth responses of subalpine fir to climatic variability in the Pacific Northwest
We studied regional variation in growth-limiting factors and responses to climatic variability in subalpine forests by analyzing growth patterns for 28 tree-ring growth chronologies from subalpine fir (Abies lasiocarpa (Hook.) Nutt.) stands in the Cascade and Olympic Mountains (Washington and Oregon, U.S.A.). Factor analysis identified four distinct time series of common growth patterns; the domin
Authors
David W. Peterson, David L. Peterson, Gregory J. Ettl
Residency and movement patterns of wintering Dunlin in the Willamette Valley of Oregon
In the winters of 1998-1999 and 1999-2000, we tracked 67 radio-marked Dunlin (Calidris alpina) throughout the complex agricultural landscape of the Willamette Valley of Oregon. Individual birds were tracked across 8-week sampling periods and indicated a high degree of regional fidelity throughout the three winter sampling periods. Birds exhibited varied degrees of fidelity to specific wetland site
Authors
P.M. Sanzenbacher, S. M. Haig